This invention relates to disinfecting lenses, such as contact lenses. In particular, the invention relates to methods useful to quickly and effectively disinfect contact lenses.
Contact lenses should be periodically disinfected to protect the wearer's eyes from infection and to improve the wearer's comfort. It is often desirable that lens disinfecting be accomplished quickly, e.g., for the convenience of the wearer. However, conventional fast-acting disinfectants that are used with contact lenses have a high potential to cause eye irritation. A disinfectant which can be easily and effectively dissipated after use would be advantageous to reduce the chance of eye irritation.
Stockel et al U.S. Pat. No. 4,499,077 discloses an antimicrobial composition for soft contact lenses including an oxidizing agent such as an oxyhalogen compound, e.g., stabilized chlorine dioxide, or hydrogen peroxide, and a polymeric germicide, e.g., a quaternary ammonium polymer or an amino and/or imino polymer or salts thereof. Stockel et al U.S. Pat. No. 4,654,208 discloses an antimicrobial composition for contact lenses including an aqueous solution of a germicidal polymeric nitrogen compound and an oxidizing agent, e.g., chlorine dioxide, stabilized chlorine dioxide or hydrogen peroxide, to potentiate the activity of the germicidal polymeric nitrogen compound at low concentrations. The Stockel et al patents characterize the "polymeric germicides" and the "germicidal polymeric nitrogen compounds" as positively charged, nitrogen-containing cationic polymers, such as certain quaternary ammonium polymers and polymeric amino and/or imino compounds, e.g., polydiguanides. Neither of these Stockel et al patents relate to contact lens disinfecting compositions without such positively charged, nitrogen-containing cationic polymers.
In addition to being disinfected, the contact lens should be cleaned, e.g., of protein-based debris which accumulates on the lens during use. Such lens cleaning is often done in the presence of one or more enzymes. See, for example, Karageozian U.S. Pat. No. 3,910,296. In many instances, a complete lens maintenance procedure involves first enzymatic cleaning followed by a separate lens disinfecting step.